1. Technical Field
The present disclosure relates to anatomy detection and, more specifically, to robust anatomy detection though local voting and prediction.
2. Discussion of Related Art
Computed tomography (CT) imaging is the practice of visualizing the internal structure of a subject using a series of x-rays taken at multiple angles, the data from which may be combined and rendered by a computer system for illustrating the internal structure of the subject in three-dimensions. While CT imaging is relatively safe, it does involve exposure to ionizing radiation, which could become harmful in patients. Accordingly, it is generally considered prudent to limit the acquisition of image data to a particular field of the subject's body. By scanning only this field, the patient's exposure to ionizing radiation can be limited and the time needed to acquire the image reduced. Moreover, by limiting the scanning field, it is possible to acquire the desired image data more quickly and with less use of resources than if the entire body was scanned.
It is therefore important to be able to correctly identify the scanning field so that the resulting CT image captures the desired structural data. If the scanning field is selected to be sufficiently large, then there is less risk of missing pertinent structural data. However, the more precise the field is, the faster the scan can be performed and the less the subject is exposed to potentially harmful ionizing radiation. Accordingly, it is desirable to select a precise scanning field that is only as large as is necessary to capture the desired structural data.
In order to set the scanning field, often the CT scanner is used to produce one or more topograms of the subject's body. A topogram is a scout image that may be used to establish where the target organs are located within the subject's body so that the scanning field may be precisely selected. The topogram appears similar to a conventional radiograph, where the outline of the subject's body may be seen with certain organs and anatomical features superimposed thereon.
Presently, the scanning field is manually determined by a human operator such as a radiology technician. The human operator uses learned knowledge of human anatomy to identify the organs to be imaged and then selects the scanning field to be scanned in detail. However, this manual determination may take an amount of time that is noticeable to the subject, and as such, there is a greater possibility that the subject may shift position between the acquisition of the topogram and the acquisition of the CT scan within the manually determined scanning field. Accordingly, the manually determined scanning field must be selected with wide margins to allow for subtle movement. Moreover, the manually selected scanning field may be slightly different each time a CT scan is performed and thus multiple CT scans, such as follow-up studies of the same patient and/or cross-patient comparisons, may be more difficult to compare owing to the inherent inconsistency of the manual field selection.